Cocrystals Enhance Biopharmaceutical and Antimicrobial Properties of Norfloxacin.

A solvate cocrystal of the antimicrobial norfloxacin (NFX) was formed by using isonicotinamide (INA) as a coformer with the solvent evaporation technique. The cocrystal formation was confirmed by performing solid-state characterization techniques. We evaluated the dissolution under supersaturated conditions and also the solubility at the vertex of triphasic domain of cocrystal and NFX in both water and Fasted-State Simulated Intestinal Fluid (FaSSIF).

Obtaining Cocrystals by Reaction Crystallization Method: Pharmaceutical Applications.

Cocrystals have gained attention in the pharmaceutical industry due to their ability to improve solubility, stability, in vitro dissolution rate, and bioavailability of poorly soluble drugs. Conceptually, cocrystals are multicomponent solids that contain two or more neutral molecules in stoichiometric amounts within the same crystal lattice. There are several techniques for obtaining cocrystals described in the literature; however, the focus of this article is the Reaction Crystallization Method (RCM).

Solid-State Characterization and Compatibility Studies of Penciclovir, Lysine Hydrochloride, and Pharmaceutical Excipients.

The physical and chemical characterization of the solid-state properties of drugs and excipients is fundamental for planning new formulations and developing new strategies for the treatment of diseases. Techniques such as differential scanning calorimetry, thermogravimetry, X-ray powder diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy are among the most commonly used techniques for these purposes. Penciclovir and lysine are individually used to treat the herpes virus.

Solid-State Characterization of Different Crystalline Forms of Sitagliptin.

Sitagliptin is an inhibitor of the enzyme dipeptidyl peptidase-4, used for the treatment of type 2 diabetes mellitus. The crystal structure of active pharmaceutical solids determines their physical and chemical properties. The polymorphism, solvates and hydrates can influence the free energy, thermodynamic parameters, solubility, solid-state stability, processability and dissolution rate, besides directly affecting the bioavailability.

In Vitro Dissolution Profile of Dapagliflozin: Development, Method Validation, and Analysis of Commercial Tablets.

Dapagliflozin was the first of its class (inhibitors of sodium-glucose cotransporter) to be approved in Europe, USA, and Brazil. As the drug was recently approved, there is the need for research on analytical methods, including dissolution studies for the quality evaluation and assurance of tablets. The dissolution methodology was developed with apparatus II (paddle) in 900 mL of medium (simulated gastric fluid, pH 1.

Quantitative Analysis of Norfloxacin in β-Cyclodextrin Inclusion Complexes--Development and Validation of a Stability-indicating HPLC Method.

The aim of this study was to develop and validate a simple liquid-chromatography method, with good accuracy, reproducibility and sensitivity, for the quantification of norfloxacin in β-cyclodextrin inclusion complexes. In the method validation, the parameters evaluated were linearity, limits of detection and quantification, specificity, accuracy, precision and robustness. The stability-indication property of the method was evaluated through studies on the degradation under stress conditions.

Investigation of β-cyclodextrin-norfloxacin inclusion complexes. Part 2. Inclusion mode and stability studies.

Introduction: Norfloxacin (NFX) is a broad spectrum antibiotic with low solubility and permeability, which is unstable on exposure to light and humidity.

Objective: In this study, the mode of NFX inclusion into β-cyclodextrin complexes was evaluated and a complete physical, chemical and microbiological stability study of the inclusion complexes was carried out.

Methods: Potentiometric titrations were performed to evaluate changes in the pKa of the NFX molecule due to the formation of an inclusion complex and NMR analysis demonstrated that the NFX molecule is included in the β-cyclodextrin cavity.

Solid-state evaluation and polymorphic quantification of venlafaxine hydrochloride raw materials using the Rietveld method.

Venlafaxine hydrochloride (VEN) is an antidepressant drug widely used for the treatment of depression. The purpose of this study was to carry out the preparation and solid state characterization of the pure polymorphs (Forms 1 and 2) and the polymorphic identification and quantification of four commercially-available VEN raw materials. These two polymorphic forms were obtained from different crystallization methods and characterized by X-ray Powder Diffraction (XRPD), Diffuse Reflectance Infrared Fourier Transform (DRIFT), Raman Spectroscopy (RS), liquid and solid state Nuclear Magnetic Resonance (NMR and ssNMR) spectroscopies, Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM) techniques.

Formulation development and stability studies of norfloxacin extended-release matrix tablets.

The aim of this research was to develop a new hydrophilic matrix system containing norfloxacin (NFX). Extended-release tablets are usually intended for once-a-day administration with benefits to the patient and lower discontinuation of the therapy. Formulations were developed with hydroxypropylmethylcellulose or poly(ethylene oxide) as hydrophilic polymers, with different molecular weights (MWs) and concentrations (20 and 30%).

Solid-state characterization and dissolution properties of Fluvastatin sodium salt hydrates.

The present study reports the solid-state properties of Fluvastatin sodium salt crystallized from different solvents for comparison with crystalline forms of the commercially available raw material and United States Pharmacopeia (USP) reference standard. Fluvastatin (FLV) samples were characterized by several techniques; such as X-ray powder diffractometry, differential scanning calorimetry, thermogravimetry, liquid and solid-state nuclear magnetic resonance spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy, and scanning electron microscopy. In addition, intrinsic dissolution rate (IDR) of samples was performed in order to study the influence of crystalline form and other factors on rate and extent of dissolution.

High-performance column liquid chromatographic method for the simultaneous determination of buclizine, tryptophan, pyridoxine, and cyanocobalamin in tablets and oral suspension.

An HPLC method was developed and validated for the simultaneous determination of buclizine, tryptophan, pyridoxine, and cyanocobalamin in pharmaceutical formulations. The chromatographic separation was carried out on an RP-C18 column using a mobile phase gradient of methanol, 0.015 M phosphate buffer (pH 3.

Determination of lumiracoxib by a validated stability-indicating MEKC method and identification of its degradation products by LC-ESI-MS studies.

A stability-indicating MEKC method was developed and validated for the analysis of lumiracoxib (LMC) in pharmaceutical formulations using nimesulide as the internal standard (IS). Optimal conditions for the separation of LMC and degradation products were investigated. The method employed 50 mM borate buffer and 50 mM anionic detergent SDS solution at pH 9.

Assembled modules technology for site-specific prolonged delivery of norfloxacin.

The aim of this research was to design and study norfloxacin (NFX) release in floating conditions from compressed hydrophilic matrices of hydroxypropylmethylcellulose (HPMC) or poly(ethylene oxide) (PEO). Module assembling technology for drug delivery system manufacturing was used. Two differently cylindrical base curved matrix/modules, identified as female and male, were assembled in void configuration by friction interlocking their concave bases obtaining a floating release system.

Development and validation of a stability-indicating LC method for the determination of venlafaxine in extended-release capsules and dissolution kinetic studies.

A stability-indicating reversed-phase high-performance liquid chromatography method is developed and validated for the determination of venlafaxine hydrochloride (VEN) in extended-release capsules containing spherical beads and for dissolution studies. The method is carried out on a Luna C(18) column (250 mm x 4.6 mm) maintained at 35 degrees C.

Liquid chromatographic determination of norfloxacin in extended-release tablets.

A stability indicating reversed-phase liquid chromatography method is developed and validated for the determination of norfloxacin in a new formulation of extended-release tablets. The LC method is carried out on a Luna C(18) column (150 x 4.6 mm) maintained at 40 degrees C.

Liquid chromatographic determination of lumiracoxib in pharmaceutical formulations.

A stability-indicating reversed-phase liquid chromatography (LC) method was developed and validated for the determination of lumiracoxib in pharmaceutical formulations. The LC method was carried out on a Synergi fusion C(18) column (150 mmx4.6mm), maintained at 30 degrees C.